A field effect transistor is provided which comprises a gate electrode, a source electrode, a drain electrode, at least one organic semiconducting layer, and a hole transport layer for transferring holes from said source and drain electrodes to said organic semiconducting layer, wherein said hole transport layer comprises a layered metal chalcogenide. Processes for depositing a thin layer of a layered metal dichalcogenide on a substrate and for producing top gate structures on a layered metal chalcogenide layer in the manufacture of field effect transistors according to the invention are also provided.